The present invention concerns a polymer layer for a sensor, wherein the polymer layer has nanoparticles embedded therein which impart to the polymer layer recognizing properties as well as transducer properties, a sensor comprising such layer, and the use of the sensor for detecting and/or quantifying a target analyte.
Various sensors for determining substances of interest in a qualitative and quantitative manner have been described to date. In particular, in the fields of environmental and food technology, medicine, and biotechnology the development of precise analytical means and methods is of great interest. For example, enzyme-based sensors with electrochemical or optical transduction are widely used to determine analytes in the blood and in other body liquids.
Generally, classical sensors consist of a multilayer structure. For example, U.S. Pat. No. 6,107,083 describes an optical enzyme-based sensor with a multilayer structure which comprises, in the sequence of layers: (a) an oxygen-sensitive layer containing a luminescent dye in a light-transmissive, oxygen-permeable matrix, (b) an enzymatic layer containing an oxidative enzyme in a hydratable and oxygen-permeable matrix, and (c) a rapidly hydrating gas-permeable cover layer disposed over the enzymatic layer.
Major drawbacks of such multilayer-structured sensors are the complex buildup of the sensors involving problems with the coating compatibility of the multiple layers, the limited density of functional elements available on a planar surface, and the difficulty in controlling precisely the thickness of each layer in order to maintain reproducible diffusion processes. These processes are accompanied by unsatisfactory sensor responses and reduced signal yields.
In U.S. Pat. No. 6,238,930 B1 a different approach for a layer structure for the determination of a substance has been made by forming a micellar recognition system from two non-miscible phases, a surface-active substance and a recognition component, and by incorporating this system into a layer. The substance of interest is then detected by the interaction with the recognition component and a transducing step both occurring in the layer. The construction of the layer structure according to U.S. Pat. No. 6,238,930 B1 is complex and due to the requirement of forming appropriate micelles, the flexibility and field of application of such systems is limited. Compared to the classical multilayer-structured sensors no significant simplification could be achieved.